A study published in the Journal of Psychiatric Research uncovered elevated levels of hoarding in patients with ADHD. The findings revealed that nearly one in five patients with ADHD reported clinically significant hoarding symptoms and that inattention predicted the severity of hoarding.
Hoarding disorder (HD) involves an excessive accumulation of possessions and difficulty getting rid of these possessions. These behaviors result in a buildup of clutter, which often leads to significant distress and difficulty functioning in day-to-day life.
While hoarding behaviors tend to emerge in adolescence, many sufferers do not recognize the problem — or seek treatment — until much later in life when symptoms have significantly progressed. As a result, most studies involving participants with HD are conducted among older populations in their 50s and 60s.
One way to promote the earlier identification of HD is to study patients with disorders whose symptoms overlap with HD. While previous research has explored symptoms of HD in patients with Obsessive-Compulsive Disorder (OCD), study authors Sharon Morein-Zamir opted to focus on patients with Attention-Deficit/Hyperactivity Disorder (ADHD) — a disorder characterized by inattention and impulsivity. The authors were motivated by recent studies suggesting that people with hoarding disorder present with features of ADHD.
“Much of my research involves understanding mental health conditions relating to compulsivity and impulsivity,” explained Morein-Zamir, an associate professor at Anglia Ruskin University and co-director of the Centre for Mind and Behaivour.”As part of that I have investigated amongst other conditions aspects of ADHD, HD and OCD. I think being aware of the issues faced by patients diagnosed with any of these conditions makes one aware of the similarities and differences between them – and raises the idea of possible links.”
“My personal experience has been that the link between inattention and hoarding is well known in the HD domain (patients and clinicians). The possibility of a link does not seem to be well known at all in the ADHD research or clinical community at all. Psychiatry and the understanding of mental health is/should be moving away from compartmentalizing different aspects of a person’s experiences/symptoms and giving them separate labels.”
Morein-Zamir and her team conducted a study to explore whether patients with ADHD demonstrate higher rates of HD. A sample of 88 patients with ADHD was compared to a sample of 90 gender- and education-matched control subjects. Importantly, the control subjects did not meet criteria for ADHD, nor had they been previously diagnosed with the disorder. The two samples completed questionnaires that included assessments of ADHD symptoms (inattention, impulsivity, hyperactivity), hoarding symptoms (difficulty discarding, clutter, excessive accumulation), and OCD symptoms.
When the researchers compared the two groups, they found that patients with ADHD had higher scores on every questionnaire and subscale related to hoarding. This was underscored by roughly 20% of the ADHD sample meeting the cut-off for clinically significant hoarding, compared to only 2% of the control sample.
The findings indicate “that people with ADHD as a group can have a tendency to accumulate more, have more clutter and have difficulties discarding things – not everyone, but on average,” Morein-Zamir told PsyPost.
ADHD patients who met this threshold for hoarding had higher scores for inattention (but not impulsivity or hyperactivity) compared to ADHD patients who were below threshold. And inattention was the only significant predictor of hoarding severity among ADHD patients.
The researchers checked these findings against an independent sample of 220 people. They found that both inattention and hyperactivity/impulsivity were associated with hoarding, and that, inattention, depression, and anxiety were significant predictors of hoarding severity.
“Inattention and hoarding behaviours are along a continuum and linked across the entire population, so this can speak not just to people with diagnosed conditions,” Morein-Zamir explained.
According to the study authors, the overall findings suggest that people with ADHD should undergo routine assessments for hoarding symptoms. This may assist with the earlier identification of people with hoarding disorder, which is important since hoarding is associated with psychological distress and can severely interfere with daily life. Notably, the subgroup of ADHD patients with clinically significant hoarding symptoms had higher depression and anxiety.
“This study points to a hidden population of adults who demonstrate clinically significant hoarding symptoms,” Morein-Zamir and her colleagues write. “Greater awareness amongst clinicians, patients and their carers about the link between ADHD and hoarding could also facilitate more effective long-term management, as hoarding often gradually worsens with time.” They say the overlap between HD and ADHD may also illuminate potential therapeutic and pharmacological treatment options.
But the study, like all research, includes some limitations.
“This is the first study and relied on self report (although we cross referenced three separate questionnaires and so was more rigorous than many other self report studies) – interviewing patients one on one is very expensive and I didn’t have the resources for that – of course replication in other clinics (preferably in other countries/backgrounds, etc) are needed to see whether they also find raised levels and if so to what degree,” Morein-Zamir explained.
There is also still much to learn about the link between ADHD and hoarding. “It is likely due to the overlap in executive function difficulties seen in both populations (difficulties in planning, organising, concentrating, decision making etc.) – but that won’t be the whole story,” Morein-Zamir said. “Adverse life events, stressors and emotional aspects likely play a role as precipitating factors in both. The issue of insight is the most unclear to me – why do many of these people not ask for help or think this is impacting their lives unless specifically asked and discussed with them?”
“Also we assume that if someone with ADHD is getting treatment for their symptoms and treatment providers know they also have difficulties relating to hoarding then that knowledge will help, but in what way and exactly how is still unclear – generally knowledge is power but for that to be true one needs to know how to use the knowledge effectively.”
The study, “Elevated levels of hoarding in ADHD: a special link with inattention”, was authored by Sharon Morein-Zamir, Michael Kasese, Samuel R Chamberlain, and Estherina Trachtenberg.